JP3628112B2 - Radioactive gas waste treatment equipment - Google Patents

Description

にて算出される値に基づいて評価することを特徴とする。
【００２０】
【発明の実施の形態】
以下、本発明に係る放射性気体廃棄物処理装置の実施形態について、図面を参照して説明する。なお、装置の全体構成は図４に示したものとほぼ同様であるから、説明を省略する。
【００２１】
［第１の実施形態］（図１）
図１は、本実施形態による放射性気体廃棄物処理装置の排ガス再結合器３の構成を示す断面図である。
【００２２】
この図１に示すように、排ガス再結合器３は、密閉型の球状の容器３ａに排ガス入口ノズル３１、触媒充填口３２および処理済みガス流出用の排ガス出口ノズル３３を設けた構成とされている。容器３ａは、耐圧部材としての半球状の２枚の鏡板を、底縁を傾けた状態で互いに接合し、溶接固定した構成とされている。容器３ａの上部には、排ガス入口ノズル３１と触媒充填口３２とを兼用する管台３ｂが設けられている。排ガス入口ノズル３１と排ガス出口ノズル３３とは、容器３ａ内のほぼ中心を通る直線上で対向する配置とされている。すなわち、容器３ａにはフランジ締結構造の排ガス入口ノズル３１を設け、配管３４とフランジ３５によって締結している。そして、この容器３ａに触媒３９を充填し、容器３ａへの排ガス入口部より排ガス出口部に至る容器３ａ内の流れが一次元的となるようにしてある。
【００２３】
また、排ガス再結合器３の排ガス入口ノズル３１から容器３ａ内に通じる排ガス流路、つまり排ガス入口ノズル３１と配管３４のフランジ３５締結部との間にリング状の偏向板支持板３６が挟持され、偏向板３８が偏向板支持ロッド３７を介して吊り下げられている。偏向板３８は、触媒３９内での排ガスの拡散を行わせるもので、ほぼ半球形状をなし、上側に曲面を向けた状態で懸架されている。この吊下型偏向板３８の全面に、排ガスを通過させる多数の孔４０が穿設され、この孔４０の径は偏向板３８の中央部から端部へ向かうにつれて次第に拡大されている。
【００２４】
排ガス出口ノズル３３は、容器３ａの内底部で開口するとともに、容器３ａの側部に亘って立上がる湾曲管３３ａにより構成されている。この湾曲管４１の容器３ａ内での下端部を囲む配置で、触媒３９の保持と触媒３９の下流側での飛散防止を兼用するほぼ半球形のスクリーン４１が上側に曲面を向けた状態で配設され、このスクリーン４１は触媒３９の自重に耐え得る強度を有するものとされている。半球形のスクリーン４１は、排ガスの流路を確保するべくパンチングメタルにより構成されるとともに、熱応力緩和用として相対変位が可能な二重構造とされ、かつ二重構造の半球形スクリーン４１のうち外側に配置する一方のスクリーン４１ａは排ガス出口ノズル３３に固定され、内側に配置する他方のスクリーン４１ｂは容器３ａ底部に固定されている。
【００２５】
容器３ａの側部には、輸送用の吊り耳と据え付け具とを兼用する複数の中間ラグ４２が周方向に等間隔で設けられ、この各中間ラグ４２には、それぞれ円形孔４３が穿設されている。
【００２６】
このような構成の排ガス再結合器３を有する本実施形態によれば、密閉型の容器３ａを半球形鏡板による全球形構造としたので、他の形状、例えば従来の円筒形などと比較して剛性が高い。即ち、板厚が同じであれば触媒充填容量を増加することができ、また触媒容量が同一であれば板厚を低減することができる。また、２枚の半球形の鏡板３０の溶接線４４と排ガス出口ノズル３３および中間ラグの取付けに当たっては、半球形鏡板３０の溶接線４４を傾けたことにより、互いに干渉を回避することができる。
【００２７】
そして、配管３４より装置上部の排ガス入口ノズル３１より排ガス出口ノズル３３に至る容器３ａ内の排ガスの流れは、排ガス入口ノズル３１および排ガス出口ノズル３３が直線上に配置されているため、偏流となることがなく、円滑な流れとなる。また、従来の排ガス再結合器の上部に設置していた触媒充填のための開口部（触媒充填口）に代えて、排ガス入口ノズル３１の配管３４をフランジ３５で締結した構造としたので、触媒充填時は、配管３４が取り外し可能であり、別途に触媒充填口を設ける必要なく、触媒３９の充填作業等が可能となる。
【００２８】
また、吊下型の偏向板３８の全面に径の異なる孔４０を穿設し、この孔４０は偏向板３８の中心部で小さく、外周に向かうにつれて径を増大させるようにしたことで、良好な拡散整流効果が得られる。また、偏向板３８は、排ガス入口ノズル３１とフランジ３５と配管３４のフランジ締結部との間に挟み込んだリング状の偏向板支持板３６により、偏向板支持ロッド３７を介して懸架されているため、これについても、触媒充填時等の分解が可能である。
【００２９】
しかも、排ガス出口ノズル３３については、触媒３９を保持し且つ下流への流出防止のため、２枚の半球形スクリーン４１ａ，４１ｂが、一方は排ガス出口ノズル３３に溶接にて固定され、他方は容器３ａの半球形鏡板３０の下側内面に溶接にて固定され二重化されているので、これにより、容器３ａと排ガス出口ノズル３３の熱変位を吸収でき、スクリーン部に過大な熱応力が発生することを防止できるようになる。
【００３０】
さらに、排ガス出口ノズル３３は、容器３ａ内部で湾曲して取出し方向が機器側面側に設けられている。これにより、従来容器下部に設置されていた排ガス出口ノズル３３を容器３ａの側面に設置できるため、支持構造としての脚部の短尺化が図れ、中間ラグ４２による支持構造が可能となる。また、容器３ａの外周には等間隔に機器支持用の中間ラグ４２を外周に均等間隔に配置し、これに機器輸送用として円形孔４３を穿設したことにより、吊り耳を別途設ける必要がない。
【００３１】
さらにまた、排ガスの流れの一次元的拡散整流効果により触媒反応の均一化が図れ、充填触媒３９の全体有効活用および容器３ａ内部の温度分布の均一化が図れさらに、排ガス出口ノズル３３の改善により支持構造の改善、即ち脚の短尺化または省略が図れ、耐震性が向上できるとともに、排ガス出口ノズル３３の設置方法の改善により触媒３９の下流への飛散防止の本質的改善が図れる。
【００３２】
また、本実施形態においては、排ガス再結合器３内に充填する触媒３９量の決定に際しての空筒速度算出に用いる評価断面積Ａ（ｍ^２ ） は、触媒３９充填層高をＨ（ｍ）、球状の容器３ａの内半径をＲ（ｍ）としたとき、各触媒３９充填層毎の断面積を平均化した下記の式
【数３】

にて算出される値に基づいて評価するようにしている。
【００３３】
このような評価構成によれば、機器基本設計の観点から、装置に充填する触媒量の決定に際し、空筒速度算出に用いる評価断面積を算出することにより、充填触媒容量を合理的に決定することができる。
【００３４】
［第２の実施形態］（図２）
図２は本実施形態による放射性気体廃棄物処理装置の排ガス再結合器３を示している。
【００３５】
本実施形態が第１の実施形態と異なる点は、図１に示した排ガス再結合器３における中間ラグ支持構造に代えて、スカート５０による支持構造とした点である。他の構成については、第１実施形態のものと同様であるから、図２に図１と同一の符号を付して、説明を省略する。
【００３６】
このような構成の第２実施形態によれば、容器３ａをスカート５０によって支持する構造としたことで、中間ラグ構造と比較して、基礎関係の構造の簡素化が図れ、耐震評価を容易に行うことができる。
【００３７】
［第３の実施形態］（図３）
図３は本実施形態による放射性気体廃棄物処理装置の排ガス再結合器３を示している。
【００３８】
本実施形態が前記各実施形態と異なる点は、図１に示した排ガス再結合器３における配管３４との取合部を半球形鏡板３０に直接取付けた排ガス入口ノズル３１のフランジ部５９によって構成した点にある。
【００３９】
また、排ガス出口部については、図１における排ガス出口ノズル３３とスクリーンの機能を併有するように、構造を変化させたものである。即ち、本実施形態の排ガス出口ノズル６０は、容器３ａの内底部で開口するとともに容器３ａの側方へ向かって横長に伸びる直管６０ａにより構成されている。この直管６０ａの下面側にスクリーン６１が取付けられている。このスクリーン６１は下向きとして、直管６０ａの底部に配置したことで、触媒３９の荷重を受けずに済む構成としてある。他の構成については、第１実施形態のものと同様であるから、図２に図１と同一の符号を付して、説明を省略する。
【００４０】
このような構成の第３の実施形態によれば、排ガス出口ノズル６０の容器３ａ内での占有面積が縮小化され、容器３ａ内での排ガスの流れの均一化および触媒３９有効容積の確保が可能である。また、排ガスは、配管３４より排ガス再結合器３の装置上部に設けられた排ガス入口ノズル３１を経由して容器３ａ内に流入する。本実施形態の排ガス再結合器３においても、排ガス入口ノズル３１と排ガス出口ノズル６０が一次元的に配置されているため排ガス流の偏流が防止される。また、排ガス入口部に設置された吊下型偏向板３８により、排ガスは容器３ａ内へ均一に拡散され、さらに吊下型偏向板３８全面には中央部から端部へ向かうにつれて径を増加させた孔４０を全面に穿設し、これにより排ガス流は拡散整流され触媒３９の上面部にて均一な流量分布が得られるようになり、充填した触媒３９の有効且つ均一な反応度維持が可能となる。
【００４１】
【発明の効果】
以上で詳述したように、本発明によれば、構造強度的観点からは、耐圧部を球形鏡板による全球形構造としたことにより、容器としての強度向上の効果が向上し、容器の必要板厚の低減により機器重量の低減が図れる。また、触媒の下流への飛散防止のためのスクリーンをパンチングメタル等で製作した半球形のものとし、かつ二重構造としたことで相対変位が可能となり、熱応力緩和が図れる。また、排ガス出口ノズルが機器側面に配置しているため、装置下部側の構造物の設置が不要となり、装置の支持構造の簡素化および耐震性の向上が図れる。また、排ガス出口ノズルを直管型とした場合にも、同様の効果が奏される。
【００４２】
また、再結合機能の観点からは、排ガス装置内に流入するための排ガス入口ノズルと触媒を充填するための充填口とを同一の管台で実現可能としたので、装置内の排ガスの均一な流路が確保でき、容器内の余剰空間を削減することより充填した触媒の有効利用が図れる。また、排ガス入口部に吊下型偏向板を設置し、かつ中央部から端部へ向かうにつれて径を徐々に増大させて全面に孔を穿設したことにより、触媒内での排ガスの均一な拡散を行わせることができる。
【００４３】
しかも、機器取扱の点からは、触媒充填口と排ガス入口部を機能的に同一管台で併用可能となり、また中間ラグに穿設した円形状の孔を装置の輸送、据え付けのための吊り耳として利用することで、装置に別途に吊り耳を設置する必要がない等の効果が奏される。。
【００４４】
さらに、機器基本設計の観点からは、装置に充填する触媒量の決定に際しての空筒速度算出に用いる評価断面積Ａ（ｍ^２ ）を、触媒充填高をＨ（ｍ）、球形の内半径をＲ（ｍ）としたとき、
【数４】

として算出することにより、充填触媒容量を合理的に決定できる効果が奏される。
【図面の簡単な説明】
【図１】本発明に係る放射性気体廃棄物処理装置の排ガス再結合器の第１の実施形態を示す一部切断断面図。
【図２】本発明に係る放射性気体廃棄物処理装置の排ガス再結合器の第２の実施形態を示す一部切断断面図。
【図３】本発明に係る放射性気体廃棄物処理装置の排ガス再結合器の第３の実施形態を示す一部切断断面図。
【図４】放射性気体廃棄物処理装置における排ガス再結合器周辺の系統構成を示す系統図。
【図５】従来の放射性気体廃棄物処理装置の排ガス再結合器の構成を示す一部切断断面図。
【符号の説明】
１ 蒸気式空気抽出器
２ 排ガス予熱器
３ 排ガス再結合器
３ａ 容器
３ｂ 管台
４ 排ガス復水器
５ スタック
６，７，８ 配管
３１ 排ガス入口ノズル
３２ 触媒充填口
３３，６０ 排ガス出口ノズル
３４ 配管
３５ フランジ
３６ 偏向板支持リング
３７ 偏向板支持ロッド
３８ 吊下型偏向板
３９ 触媒
４０ 孔
４１ スクリーン
４２ 中間ラグ
５０ スカート[0001]
[Industrial application fields]
The present invention relates to a radioactive gas waste treatment apparatus installed in a nuclear power plant or the like, and in particular, by recombining exhaust gas generated by radiolysis of water in a nuclear reactor, for example, hydrogen and oxygen by a catalytic reaction. The present invention relates to a radioactive gas waste treatment apparatus with an improved exhaust gas recombiner that makes exhaust gas less than the flammability limit.
[0002]
[Prior art]
As is well known in the past, in nuclear power plants, etc., air flowing into the main condenser, hydrogen and oxygen by radioactive decomposition of water in the reactor, fission product gas that is activated in the reactor, etc. Are generated and processed as a waste gas by a radioactive gas waste treatment apparatus.
[0003]
As shown schematically in FIG. 4, the radioactive gas waste treatment apparatus includes a gas extractor 1 as a steam-type air extractor that extracts exhaust gas from a main condenser (not shown), and an exhaust gas preheater that preheats the extracted exhaust gas. 2, an exhaust gas recombiner 3 for recombining the preheated exhaust gas by a catalytic reaction and processing it to a state below the flammability limit, and an exhaust gas condenser 4 for condensing the exhaust gas. 6, 7 and 8 are connected. Although not shown, an exhaust gas precooler, an exhaust gas dryer, an activated carbon rare gas holdup tower, an exhaust gas particle filter, an exhaust gas vacuum pump facility, and the like are sequentially installed on the downstream side of the exhaust gas condenser 4. It is connected. FIG. 4 shows an example in which each system (exhaust gas preheater 2, exhaust gas recombiner 3 and exhaust gas recombiner 4) is installed in two systems, and one system is a spare.
[0004]
The exhaust gas preheater 2 is installed on the upstream side of the exhaust gas recombiner 3 and superheats the exhaust gas to an overheated state in order to maintain the catalytic reactivity. The exhaust gas recombiner 3 is a device that requires high temperature conditions due to heat of catalytic reaction, and is also a device that requires high pressure conditions due to a hydrogen explosion. The exhaust gas condenser 4 condenses the water vapor used for exhaust gas extraction and the water vapor generated by recombination into condensed water.
[0005]
In such a radioactive gas waste treatment apparatus, after the exhaust gas is extracted by the gas extractor 1, it is sequentially sent to the downstream exhaust gas preheater 2, the exhaust gas recombiner 3, and the exhaust gas condenser 4 to be processed. After the radioactivity is reduced below the allowable limit, it is released from the stack 5 into the atmosphere. Condensate condensed in the exhaust gas condenser 4 is returned to a main condenser (not shown).
[0006]
FIG. 5 shows a conventional structure of the exhaust gas recombiner 3 which is the main equipment of the above-described radioactive gas waste treatment apparatus. As shown in FIG. 5, the exhaust gas recombiner 3 includes an upper end plate 10 and a lower end plate 11 as pressure-resistant members that satisfy a high temperature and high pressure condition, and a body plate 12 that connects the upper end plate 10 and the lower end plate 11. It has the airtight container 3a comprised by these. A catalyst filling port 14 for filling the catalyst 13 is provided in the upper part of the container 3a, and a screen 15 for holding the catalyst 13 and a screen 16 for preventing the catalyst 13 from flowing out downstream are provided inside. Is provided. An exhaust gas inlet nozzle 17 for introducing exhaust gas is provided on the side of the container 3a, and a deflection plate 18 for deflecting the exhaust gas upward is provided inside the exhaust gas inlet nozzle 17. Further, an exhaust gas outlet nozzle 19 for discharging the treated exhaust gas is provided at the lower part of the container 3a. In addition, the suspension ear | edge 20 used at the time of transportation and installation of an apparatus and the leg 21 for supporting the container 3a whole are provided.
[0007]
In such a configuration, the exhaust gas flows into the exhaust gas recombiner 3 from the exhaust gas inlet nozzle 17, is deflected by the deflection plate 18, and then passes through the catalyst 13. During the passage of the catalyst, hydrogen and oxygen in the exhaust gas react with each other by a catalytic reaction to become water vapor, whereby the exhaust gas falls below the flammability limit and flows out from the exhaust gas outlet nozzle 19.
[0008]
[Problems to be solved by the invention]
By the way, the exhaust gas recombiner 3 of the radioactive gas waste treatment apparatus is a high-temperature and high-pressure container, and therefore the necessary plate thickness required for strength is inevitably increased. Further, in the conventional exhaust gas recombiner 3, the exhaust gas inlet nozzle 17 and the exhaust gas outlet nozzle 19 are arranged orthogonally, so that the exhaust gas is liable to drift in the container, and the entire packed catalyst cannot be effectively used. There is sex. In addition, an extra space is generated in the container 3a due to the arrangement of each nozzle, and the exhaust gas outlet nozzle 19 is installed at the lower part of the device, so that the length of the leg 21 supporting the entire container becomes long, and the rigidity including the leg and the like is increased. There was a problem that maintenance was necessary.
[0009]
The present invention has been made in view of such circumstances, and it is possible to reduce the size and thickness of the exhaust gas recombiner, and to make the flow of exhaust gas uniform in the exhaust gas recombiner and to make the packed catalyst effective. An object of the present invention is to provide a radioactive gas waste treatment device that can improve performance by use and can also improve the earthquake resistance of an exhaust gas recombiner.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the invention of claim 1 is a gas extractor for extracting exhaust gas generated in nuclear facilities, an exhaust gas preheater for preheating the extracted exhaust gas, and recombining the preheated exhaust gas by catalytic reaction. A waste gas reprocessing apparatus comprising an exhaust gas recombiner for processing to a state below a flammability limit, wherein the exhaust gas recombiner is disposed in a sealed container with an exhaust gas inlet nozzle, a catalyst filling port and a treated An exhaust gas outlet nozzle for gas outflow is provided, wherein the exhaust gas recombiner has a spherical container, and the exhaust gas inlet nozzle and the exhaust gas outlet nozzle are opposed to each other on a straight line passing through substantially the center of the container. It is characterized by that.
[0011]
According to a second aspect of the present invention, in the radioactive gas waste treatment apparatus according to the first aspect of the present invention, a nozzle that serves both as an exhaust gas inlet nozzle and a catalyst filling port is provided at the upper part of the exhaust gas recombiner. .
[0012]
According to a third aspect of the present invention, there is provided the radioactive gas waste treatment apparatus according to the second aspect, wherein the exhaust gas is diffused in the catalyst in the exhaust gas flow path leading from the exhaust gas inlet nozzle of the exhaust gas recombiner into the container. The suspension type deflecting plate having a shape is arranged with the curved surface facing upward.
[0013]
According to a fourth aspect of the present invention, there is provided the radioactive gas waste treatment apparatus according to the third aspect, wherein a number of holes through which the exhaust gas passes are formed on the entire surface of the suspension type deflection plate, and the diameter of the holes is the center of the deflection plate. It is characterized by being gradually enlarged from the part toward the end.
[0014]
According to a fifth aspect of the present invention, in the radioactive gas waste treatment apparatus according to any one of the first to fourth aspects, the exhaust gas outlet nozzle of the exhaust gas recombiner opens at the inner bottom portion of the container and the side portion of the container It is characterized by comprising a curved tube that rises over the distance.
[0015]
The invention of claim 6 is the radioactive gas waste treatment apparatus according to claim 5, wherein the bent tube constituting the exhaust gas outlet nozzle surrounds the lower end portion in the container, and the catalyst is held and the catalyst is disposed downstream. A substantially hemispherical screen that also serves to prevent scattering is disposed with the curved surface facing upward, and this screen has a strength that can withstand the dead weight of the catalyst.
[0016]
According to a seventh aspect of the present invention, in the radioactive gas waste treatment apparatus according to the sixth aspect, the hemispherical screen is made of a punching metal so as to secure a flow path for the exhaust gas, and is capable of relative displacement for thermal stress relaxation. One of the hemispherical screens of the double structure 2 is fixed to the exhaust gas outlet nozzle, and the other is fixed to the bottom of the container.
[0017]
The invention according to claim 8 is the radioactive gas waste treatment apparatus according to any one of claims 1 to 7, wherein the side of the container of the exhaust gas recombiner is used as a suspension ear for transportation and a fixture. An intermediate lug with a circular hole is provided.
[0018]
The invention according to claim 9 is the radioactive gas waste treatment apparatus according to any one of claims 1 to 4 or claim 8, wherein the exhaust gas outlet nozzle of the exhaust gas recombiner opens at the inner bottom of the container. It is characterized by comprising a straight pipe extending horizontally long toward the side of the container.
[0019]
According to a tenth aspect of the present invention, there is provided the radioactive gas waste treatment apparatus according to any one of the first to ninth aspects, wherein the evaluation is used for calculating an empty cylinder speed when determining the amount of catalyst charged in the exhaust gas recombiner. The area A (m ² ) is the following equation obtained by averaging the cross-sectional area of each catalyst packed bed, where the catalyst packed bed height is H (m) and the inner radius of the spherical container is R (m). 2]

It is characterized by evaluating based on the value calculated in (1).
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a radioactive gas waste disposal apparatus according to the present invention will be described with reference to the drawings. Note that the overall configuration of the apparatus is substantially the same as that shown in FIG.
[0021]
[First Embodiment] (FIG. 1)
FIG. 1 is a cross-sectional view showing the configuration of the exhaust gas recombiner 3 of the radioactive gas waste treatment apparatus according to the present embodiment.
[0022]
As shown in FIG. 1, the exhaust gas recombiner 3 is configured such that a closed spherical container 3a is provided with an exhaust gas inlet nozzle 31, a catalyst filling port 32, and an exhaust gas outlet nozzle 33 for outflow of treated gas. Yes. The container 3a has a configuration in which two hemispherical end plates as pressure-resistant members are joined to each other with their bottom edges inclined and fixed by welding. At the upper part of the container 3a, a nozzle 3b serving as both the exhaust gas inlet nozzle 31 and the catalyst filling port 32 is provided. The exhaust gas inlet nozzle 31 and the exhaust gas outlet nozzle 33 are arranged to face each other on a straight line passing through the substantially center in the container 3a. That is, the exhaust gas inlet nozzle 31 having a flange fastening structure is provided in the container 3 a and fastened by the pipe 34 and the flange 35. The container 3a is filled with the catalyst 39 so that the flow in the container 3a from the exhaust gas inlet portion to the container 3a to the exhaust gas outlet portion is one-dimensional.
[0023]
Further, a ring-shaped deflecting plate support plate 36 is sandwiched between the exhaust gas flow path leading from the exhaust gas inlet nozzle 31 of the exhaust gas recombiner 3 into the container 3 a, that is, between the exhaust gas inlet nozzle 31 and the flange 35 fastening portion of the pipe 34. The deflection plate 38 is suspended via the deflection plate support rod 37. The deflecting plate 38 diffuses the exhaust gas in the catalyst 39, has a substantially hemispherical shape, and is suspended with the curved surface facing upward. A large number of holes 40 through which the exhaust gas passes are formed on the entire surface of the suspended deflection plate 38, and the diameter of the holes 40 is gradually enlarged from the central portion toward the end portion of the deflection plate 38.
[0024]
The exhaust gas outlet nozzle 33 is configured by a curved tube 33a that opens at the inner bottom portion of the container 3a and rises over the side portion of the container 3a. The curved tube 41 is disposed so as to surround the lower end portion in the container 3a, and the substantially hemispherical screen 41 that holds the catalyst 39 and prevents scattering on the downstream side of the catalyst 39 is arranged with the curved surface facing upward. The screen 41 is strong enough to withstand the dead weight of the catalyst 39. The hemispherical screen 41 is made of a punching metal so as to secure an exhaust gas flow path, and has a double structure capable of relative displacement for thermal stress relaxation. One screen 41a arranged outside is fixed to the exhaust gas outlet nozzle 33, and the other screen 41b arranged inside is fixed to the bottom of the container 3a.
[0025]
A plurality of intermediate lugs 42 serving both as suspension ears and fixtures are provided at equal intervals in the circumferential direction on the side of the container 3a, and circular holes 43 are formed in the intermediate lugs 42, respectively. Has been.
[0026]
According to the present embodiment having the exhaust gas recombiner 3 having such a configuration, since the sealed container 3a has a spherical structure with a hemispherical end plate, compared with other shapes such as a conventional cylindrical shape. High rigidity. That is, if the plate thickness is the same, the catalyst filling capacity can be increased, and if the catalyst volume is the same, the plate thickness can be reduced. Further, when the welding lines 44 of the two hemispherical end plates 30 and the exhaust gas outlet nozzle 33 and the intermediate lug are attached, the welding lines 44 of the hemispherical end plates 30 are inclined, so that interference can be avoided.
[0027]
The flow of the exhaust gas in the vessel 3a from the pipe 34 to the exhaust gas inlet nozzle 31 at the upper part of the apparatus to the exhaust gas outlet nozzle 33 is uneven because the exhaust gas inlet nozzle 31 and the exhaust gas outlet nozzle 33 are arranged in a straight line. Without a smooth flow. In addition, instead of the catalyst filling opening (catalyst filling port) installed in the upper part of the conventional exhaust gas recombiner, the pipe 34 of the exhaust gas inlet nozzle 31 is fastened by a flange 35. At the time of filling, the piping 34 can be removed, and it is not necessary to provide a separate catalyst filling port, and the filling work of the catalyst 39 can be performed.
[0028]
Further, a hole 40 having a different diameter is formed on the entire surface of the suspension type deflection plate 38, and the hole 40 is small at the central portion of the deflection plate 38 and increases in diameter toward the outer periphery. A good diffusion rectification effect. Further, the deflection plate 38 is suspended via a deflection plate support rod 37 by a ring-shaped deflection plate support plate 36 sandwiched between the exhaust gas inlet nozzle 31, the flange 35 and the flange fastening portion of the pipe 34. This can also be decomposed when the catalyst is filled.
[0029]
Moreover, with respect to the exhaust gas outlet nozzle 33, two hemispherical screens 41a and 41b are fixed to the exhaust gas outlet nozzle 33 by welding in order to hold the catalyst 39 and prevent the outflow to the downstream, and the other is a container. Since it is fixed by welding to the lower inner surface of the hemispherical end plate 30 of 3a and doubled, this can absorb the thermal displacement of the container 3a and the exhaust gas outlet nozzle 33, and excessive thermal stress is generated in the screen portion. Can be prevented.
[0030]
Further, the exhaust gas outlet nozzle 33 is curved inside the container 3a and the take-out direction is provided on the side surface of the device. As a result, the exhaust gas outlet nozzle 33 that has conventionally been installed at the lower part of the container can be installed on the side surface of the container 3a, so that the leg portion as the support structure can be shortened, and the support structure by the intermediate lug 42 becomes possible. Further, the intermediate lugs 42 for supporting the devices are arranged at equal intervals on the outer periphery of the container 3a, and the circular holes 43 are formed on the outer periphery for transporting the devices, so that it is necessary to separately provide hanging ears. Absent.
[0031]
Further, the catalyst reaction can be made uniform by the one-dimensional diffusion rectification effect of the exhaust gas flow, the entire catalyst 39 can be effectively used, and the temperature distribution inside the container 3a can be made uniform. Further, the exhaust gas outlet nozzle 33 can be improved. The support structure can be improved, that is, the legs can be shortened or omitted, and the earthquake resistance can be improved. In addition, the improvement in the installation method of the exhaust gas outlet nozzle 33 can substantially improve the prevention of scattering of the catalyst 39 downstream.
[0032]
Further, in this embodiment, the evaluation cross-sectional area A (m ² ) used for calculating the empty cylinder speed when determining the amount of the catalyst 39 to be filled in the exhaust gas recombiner 3 is obtained by setting the catalyst 39 packed bed height to H (m). When the inner radius of the spherical container 3a is R (m), the following equation is obtained by averaging the cross-sectional area of each packed bed of the catalyst 39:

The evaluation is performed based on the value calculated in (1).
[0033]
According to such an evaluation configuration, from the viewpoint of equipment basic design, when determining the amount of catalyst to be charged in the apparatus, the charged catalyst capacity is rationally determined by calculating the evaluation cross-sectional area used for calculating the empty cylinder speed. be able to.
[0034]
[Second Embodiment] (FIG. 2)
FIG. 2 shows the exhaust gas recombiner 3 of the radioactive gas waste treatment apparatus according to the present embodiment.
[0035]
This embodiment is different from the first embodiment in that a support structure using a skirt 50 is used instead of the intermediate lug support structure in the exhaust gas recombiner 3 shown in FIG. Since the other configuration is the same as that of the first embodiment, the same reference numerals as those in FIG.
[0036]
According to the second embodiment having such a configuration, the structure in which the container 3a is supported by the skirt 50 makes it possible to simplify the basic structure as compared with the intermediate lug structure and facilitate seismic evaluation. It can be carried out.
[0037]
[Third Embodiment] (FIG. 3)
FIG. 3 shows the exhaust gas recombiner 3 of the radioactive gas waste treatment apparatus according to this embodiment.
[0038]
The present embodiment is different from the above embodiments in that it is constituted by a flange portion 59 of the exhaust gas inlet nozzle 31 in which the coupling portion with the pipe 34 in the exhaust gas recombiner 3 shown in FIG. 1 is directly attached to the hemispherical end plate 30. It is in the point.
[0039]
Further, the structure of the exhaust gas outlet portion is changed so as to have the functions of the exhaust gas outlet nozzle 33 and the screen in FIG. That is, the exhaust gas outlet nozzle 60 of the present embodiment is configured by a straight pipe 60a that opens at the inner bottom portion of the container 3a and extends laterally toward the side of the container 3a. A screen 61 is attached to the lower surface side of the straight pipe 60a. The screen 61 is faced down and arranged at the bottom of the straight pipe 60a, so that the load of the catalyst 39 is not required. Since the other configuration is the same as that of the first embodiment, the same reference numerals as those in FIG.
[0040]
According to the third embodiment having such a configuration, the area occupied by the exhaust gas outlet nozzle 60 in the container 3a is reduced, the flow of exhaust gas in the container 3a is made uniform, and the effective volume of the catalyst 39 is ensured. Is possible. Further, the exhaust gas flows into the container 3a from the pipe 34 via the exhaust gas inlet nozzle 31 provided in the upper part of the exhaust gas recombiner 3. Also in the exhaust gas recombiner 3 of the present embodiment, the exhaust gas inlet nozzle 31 and the exhaust gas outlet nozzle 60 are arranged one-dimensionally, so that deviation of the exhaust gas flow is prevented. Further, the suspended deflection plate 38 installed at the exhaust gas inlet portion diffuses the exhaust gas uniformly into the container 3a, and further increases the diameter of the entire suspension deflection plate 38 from the center to the end. The exhaust gas flow is diffused and rectified so that a uniform flow rate distribution can be obtained on the upper surface of the catalyst 39, and the packed catalyst 39 can be effectively and uniformly maintained. It becomes.
[0041]
【The invention's effect】
As described in detail above, according to the present invention, from the viewpoint of structural strength, the pressure-resistant portion has a spherical structure with a spherical end plate, thereby improving the strength improvement effect as a container, and the necessary plate of the container. Equipment weight can be reduced by reducing the thickness. Further, the screen for preventing the catalyst from scattering downstream is made of a hemispherical shape made of punching metal or the like and has a double structure, so that relative displacement is possible and thermal stress can be mitigated. Further, since the exhaust gas outlet nozzle is arranged on the side of the device, it is not necessary to install a structure on the lower side of the apparatus, and the support structure of the apparatus can be simplified and the earthquake resistance can be improved. The same effect can be obtained when the exhaust gas outlet nozzle is a straight pipe type.
[0042]
Further, from the viewpoint of the recombination function, the exhaust gas inlet nozzle for flowing into the exhaust gas device and the filling port for filling the catalyst can be realized by the same nozzle, so that the exhaust gas in the device can be uniformly distributed. The flow path can be secured, and the packed catalyst can be effectively used by reducing the excess space in the container. In addition, a suspension-type deflecting plate is installed at the exhaust gas inlet, and the diameter is gradually increased from the center to the end, so that a hole is made in the entire surface, so that the exhaust gas is uniformly diffused in the catalyst. Can be performed.
[0043]
Moreover, from the point of equipment handling, the catalyst filling port and the exhaust gas inlet can be functionally used together on the same nozzle, and the circular hole drilled in the intermediate lug is a hanging ear for transporting and installing the device. As a result, there is an effect that it is not necessary to separately install a hanging ear in the apparatus. .
[0044]
Furthermore, from the viewpoint of the basic design of the equipment, the evaluation cross-sectional area A (m ² ) used for calculating the empty cylinder speed when determining the amount of catalyst charged in the apparatus, the catalyst filling height H (m), and the spherical inner radius When R (m)
[Expression 4]

As a result, it is possible to rationally determine the packed catalyst capacity.
[Brief description of the drawings]
FIG. 1 is a partially cut cross-sectional view showing a first embodiment of an exhaust gas recombiner of a radioactive gas waste treatment apparatus according to the present invention.
FIG. 2 is a partially cut cross-sectional view showing a second embodiment of the exhaust gas recombiner of the radioactive gas waste treatment apparatus according to the present invention.
FIG. 3 is a partially cut cross-sectional view showing a third embodiment of the exhaust gas recombiner of the radioactive gas waste treatment apparatus according to the present invention.
FIG. 4 is a system diagram showing a system configuration around an exhaust gas recombiner in a radioactive gas waste treatment apparatus.
FIG. 5 is a partially cut cross-sectional view showing a configuration of an exhaust gas recombiner of a conventional radioactive gas waste treatment apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Steam type air extractor 2 Exhaust gas preheater 3 Exhaust gas recombiner 3a Container 3b Pipe stand 4 Exhaust gas condenser 5 Stack 6, 7, 8 Piping 31 Exhaust gas inlet nozzle 32 Catalyst filling port 33, 60 Exhaust gas outlet nozzle 34 Piping 35 Flange 36 Deflection plate support ring 37 Deflection plate support rod 38 Suspended deflection plate 39 Catalyst 40 Hole 41 Screen 42 Intermediate lug 50 Skirt

Claims (10)

A gas extractor that extracts exhaust gas generated in nuclear facilities, an exhaust gas preheater that preheats the extracted exhaust gas, and an exhaust gas recombiner that recombines the preheated exhaust gas through a catalytic reaction to a level below the flammability limit The exhaust gas recombiner comprises a sealed container provided with an exhaust gas inlet nozzle, a catalyst filling port, and an exhaust gas outlet nozzle for discharging the treated gas. A radioactive gas waste treatment apparatus, wherein a container of an exhaust gas recombiner has a spherical shape, and the exhaust gas inlet nozzle and the exhaust gas outlet nozzle face each other on a straight line passing through substantially the center of the container. 2. The radioactive gas waste treatment apparatus according to claim 1, wherein a nozzle that serves both as an exhaust gas inlet nozzle and a catalyst filling port is provided in an upper part of a container of the exhaust gas recombiner. 3. The radioactive gas waste treatment apparatus according to claim 2, wherein a substantially hemispherical suspension type deflecting plate that diffuses the exhaust gas in the catalyst in the exhaust gas flow path leading from the exhaust gas inlet nozzle of the exhaust gas recombiner into the container. A radioactive gas waste disposal apparatus, characterized in that a curved surface faces upward. 4. The radioactive gas waste disposal apparatus according to claim 3, wherein a number of holes for allowing exhaust gas to pass through are formed in the entire surface of the suspended deflection plate, and the diameter of the holes increases from the center to the end of the deflection plate. A radioactive gas waste treatment apparatus characterized by being gradually expanded. 5. The radioactive gas waste disposal apparatus according to claim 1, wherein the exhaust gas outlet nozzle of the exhaust gas recombiner opens at the inner bottom of the container and rises over the side of the container. A radioactive gas waste treatment apparatus characterized by comprising: 6. The radioactive gas waste treatment apparatus according to claim 5, wherein the curved pipe constituting the exhaust gas outlet nozzle surrounds the lower end portion in the container, and substantially retains the catalyst and prevents the catalyst from scattering downstream. A radioactive gas waste treatment apparatus characterized in that a shaped screen is disposed with a curved surface facing upward, and the screen has a strength capable of withstanding the dead weight of the catalyst. The radioactive gas waste disposal apparatus according to claim 6, wherein the hemispherical screen is made of a punching metal so as to secure a flow path for exhaust gas, and has a double structure capable of relative displacement for thermal stress relaxation, and One of the double-structure hemispherical screens is fixed to the exhaust gas outlet nozzle, and the other is fixed to the bottom of the container. The radioactive gas waste disposal apparatus according to any one of claims 1 to 7, wherein an intermediate lug with a circular hole that serves both as a hanging ear for transportation and as a fixture is provided on a side of the container of the exhaust gas recombiner. A radioactive gas waste disposal apparatus characterized by being provided. The radioactive gas waste disposal apparatus according to any one of claims 1 to 4, or claim 8, wherein the exhaust gas outlet nozzle of the exhaust gas recombiner opens at the inner bottom of the container and faces toward the side of the container. A radioactive gas waste treatment apparatus comprising a straight pipe extending horizontally. In the radioactive gas waste treatment apparatus according to any one of claims 1 to 9, an evaluation cross-sectional area A (m ² ) used for calculating an empty cylinder speed when determining an amount of catalyst charged in an exhaust gas recombiner is: When the catalyst packed bed height is H (m) and the inner radius of the spherical container is R (m), the following equation is obtained by averaging the cross-sectional area of each catalyst packed bed

A radioactive gas waste treatment apparatus, which is evaluated based on a value calculated by

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